Foot operated air compressor



July 25, 1950 'r. E. cRocKETT 2,515,371

FOOT OPERATED AIR COMPRESSOR Filed May 5, 1947 s Shets-Shee't 1 I N V EN TOR. 7 0/746 4. 69006577 BY MAMM Jul 25, 1950 T. E. cRoeKET-r 3 FOOT OPERATED AIR COMPRESSOR Filed May-5 1947 s sheets-sh t 3 T, I w

ml I INVENTOR.

Patented July 25, 1950 UNITED STATES FOOT OPERATED AIR COMPRESSOR Thomas E. Crockett, Corpus Christi, Tex.

Application May 5, 1947, Serial No. 746,109

My invention relates to air compressors adapted ior I use in inflating automobile tires and for other purposes.

*An' important object of the invention is to provide a compressor or pump so constructed that it is manually operated by the foot or feet, in a convenient manner so that the major portion of the/weight of the operator may be applied in suchoperation.

'A further object of the invention is to provide a'c'ompressor or pump which is extremely simple in construction, and is supported substantially vertically in use, without liability of the same falling or tipping over.

"A 'further object of the invention is to provide a tire pump having a pumping cylinder equipped with inlet and outlet valves near one end thereof so that the air may readily enter the cylinder upon the up stroke of the plunger.

A'iurther object of the invention is to provide a pump of the above mentioned character having an improved plunger constructionfor effecting'a proper gas tight engagement between the plunger and pumping cylinder.

A further object of the invention is to provide a pump of the above mentioned character havin long telescoping tubes or cylinders, one of which carries the foot pedal or pedals and plunger and associated elements, whereby twisting action is eliminated and a positive guide is provided during operation.

A further object of the invention is to provide a pump of the above mentioned character having a large base and pedal or pedals secured to the reciprocatory cylinder or tube near its bottom so that there is no tendency for the pump to'tilt or fall over.

A-further object of the invention is to provide a pump of the above mentioned character which is neat and attractive in appearance.

Other objects and advantages of the invention will be apparent during the course of the following description.

* In-the accompanying drawings forming a part of this application and in which like numerals are employed to designate like parts throughout the same:

Figure l is a perspective view of a compressor or pump embodying my invention,

Figure 2 is a central vertical longitudinal section through the pump,

' Figure 3 is a plan view of the same,

Figure 4 is a horizontal section taken on line l-lof Figure 2, v

Figure 5 is a bottom plan view of the pedal unit. e

5 a marginal annular flange or foot ll.

2 Claims- (Cl. 230172) In the drawings, wherein for the purpose of illustration is shown a preferred embodiment of my invention, the numeral l0 designates a large circular horizontal base, preferably provided with Arranged "above the base 10, and concentric therewith, is a cylindrical boss 12, cast integral therewith. The base l0 and integral parts, are preferably an aluminum casting. The base I0 is provided at its top and within the boss [2 with a sump recess I3.

Formed integral with the boss I2 anclbase I0 is a radial inlet valve housing l4, having a main within the bore I5 is a check ball valve 20, to

engage the seat 18, and held against displacement by a transverse pin 2!. into an inner bore 22, leading into the sump chamber I3. Disposed diametrically opposite the air inlet valve is an air outlet valve, includin a radial valve casing 23, integral with the boss l2 ancl base It]. This valve casing has a main bore 24, provided at its inner end with a valve seat 25, 130 be engaged by a check ball valve 26, held against displacement .by a transverse pin 27. The bore 24 leads into an inner bore 28, discharging,

into the sump chamber l3. The main bore 24 has,

fitting for connection with the valve of a pneumatic tire or the like.

The numeral designates a lower stationary q vertical tube or cylinder, preferably formed of "steel, and the lowerend of this cylinder is held,

within the tubular boss l2, and is preferably screwed into the same and has a gas tight joint therewith. The cylinder 35 engages the end or rbottom 36 and the lower end of this cylinder is in free communication with the sump chamber Mounted to slide upon the lower tube or cylin der 35 is an upperreciprocatory vertical tube or cylinder 3.1, preferably formed of steel. The upper cylinder has. a freesliding fit upon the lower cylinder 35 and remains in permanent telescoping relation therewith.

Arranged within .the cylinder 3'! is a plunger rod 38, which is vertical and carries a plungerat,

"its lower end, which operates within the lower PATENTS OFFICE" v Thebore l5 leads 5 resists the action of oil. The screw threadedportion 39 carries a nut 45, having a pilotextension 46, to center the resilient washer 44 and clamp the washer 43 against the packing cup 42. The resilient washer 44 is held within .the skirt of the packing cup and spreads it radially so that it is brought into proper contact with the inner face of the cylinder 35. It is thus seen that .aplunger assembly is carried by. the lower end of. the plunger rod 38, for operation within thecy1inder35. The upward movement of thisplu-nger assembly is limited by an inwardly projecting annular bead .or shoulder .41 formed in the cylinder 35. The bead 41 is arranged well below the top .end of tube .or cylinder 35 and nearer the longitudinal center of the cylinder than itston end.

This beador shoulder forms a stop or support for a rigid steel washer 48, arranged above it, and aoompress-ible coil spring 49 engagesagainst this washer and surrounds the plunger rod 38. At its upper end, the plunger rod is rigidly sec red .to a cap 50.. This connection is prefer.- ably effected by ,forming an. apertured depression 5! in the cap 50, and this apertured depress-ion receive a reduced extension 52, of the plunger rod, the upper end of this reduced extension being spread or eened to provide, a head 53. The cap 5;] is rigidly mounted upon the top of the casing 31 by any suitable means, such as ld n Rigidly mounted upon the lower end of the upper cylinder 31 is a horizontal pedal unit 54, including oppositely arranged radial pedals 55,, having their upper surfaces roughened, as, shown. These pedals 55 are formed integral with an annular hub 58, and longitudinal reenforcing ribs 51, are preferably provided. The hub is internally threaded as shown at 58 for receiving the lower screw threaded end of the upper cylinder 31. It is thus. seen that the pedal unit is arranged at the bottom of the upper cylinder, and this provides the pump with a low center of gravity when force is applied to the pedal, reducing'the tendency for the pump to tip over. When the upper cylinder 31 is in the lowermost position the plunger assembly will project outwardly beyond thecylinder 35, with the base removed, providing excess to the plunger assembly. During the normal operation of the pump, the. plunger assembly of course reoiprocates within the lower cylinder.

The operation of the pump. is as .follows:

The flexible hose 33 is connected with a pneumatic tire, or the like. The spring 49 maintains the upper cylinder 37 in the, uppermost position whilethe pump is not bein used. A foot or feet are placed upon the pedal unit ,54, and the upper cylinder is reciprocated vertically upon the, lower relativelystationary cylinder 35. The plunger including the packing cm: 4.2 reciprocates vertically within ,the lower cylinder. Upon each upward or suction stroke of the plunger within the cylinder 35, the ball valves .20 and 4 26 move radially inwardly due to the vacuum formed in the cylinder 35. The outlet check valve 26 is closed or seated against the seat 25, and the inlet check valve simultaneously opens to admit air through the inlet opening l9, bore 15, bore 22, and sump recess l3 into the lower cylinder 35. When the next down or pumping stroke of the plunger occurs, the air in the cylinder 35 is compressed, and the ball check valves 29 and 26 move radially outwardly. The inlet check valve 2! becomes seated and closed, while the outlet or exhaust check valve 26 is opened. The compressedair therefore passes through the sump recess 13, of bore 23, bore 24, and through the'zho'se 3.31:0 the pneumatic tire, or the like.

The pump isdesigned for ease of operation in the pumping up of automobile tires. When it is used to pump up a large tire requiring relatively high air pressure, {such as a heavy truck tire, more than one person may assist in the pumping operation. For example, one person can place a foot upon each pedal 55,,and a third person can place a foot upon the cap 50,- and all three-can pump in unison.

It isto be understood that the form of my ins vent-ion herewith shown and described is to be. taken as a preferred embodiment of the same, and that various changes in the shape, Sizaaudarrangement:of parts maybe resorted to, without departing from the spirit of my invention or 1thescope of the subjoined claims. a I

Having thus described my invention, what I claim is:

bead being at an elevation well below the. v uppgr endof the-tube and nearer the longitudinalcenter of the tube than the upper end thereof, ,a substantially flat washer arranged within the upper ortion of the tube and having its man-- gmal edge mounted upon the bead and having a central opening, an upper reciprocatory tube mounted upon the lower tube and provided at its topend with a cap, a rod secured to the cap and extending within the tubes and passing through the opening in the washer and extending .below'the bead, a plunger mounted within the lower tube beneath the bead and upon the lower end of the rod, the bead serving to contact the plunger when the plunger is moved upwardly to limit such upward movement, a .com-' pression spring surrounding the rod and engaging between the cap and washer, and a foot onerated member having an intermediate portion provided with an opening for receiving the lower end of the upper tube which is held within such opening, said-foot operated member including opposltely arranged pedals carried by said "in; termediate portion. i

2. A foot operated pump for pneumatic tires and the like, comprising a relatively widebase including an upstanding portion having a sub.-

stantially verticalscrew threaded recess and-air inlet and .outlet ports in communication with such recess, check valves for the inl t "andoutlet ports, a lower upstanding tube havingits lower end screw threaded and engaging withtnu the screw threaded recess, said tube having a substantially horizontal annular bead formed from the material of the tube and projecting radially inwardly and extending entirely about the inner surface of the tube, said annular bead being at an elevation well below the upper end of the tube and nearer the longitudinal center of the tube than the upper end thereof, a. substantially fiat was-her arranged within the upper portion of the tube and having its marginal edge supported by the annular bead and being provided with a central opening, an upper reciprocatory tube mounted upon the lower tube and in telescopic relation therewith and provided at its top end with a cap and having its lower end screw threaded. a rod secured to the cap and extending within the tubes and passing through the opening in the washer and extending below the annular bead, a plunger mounted within the.

lower tube beneath the bead and upon the lower end of the rod, the bead serving to contact the plunger when the plunger is moved upwardly to limit its upward movement, a compression spring surrounding the rod and arranged between the cap and washer, and a foot operated member having an intermediate sleeve portion provided with a screw threaded opening for receiving the lower screw threaded end of the upper tube, said foot operated member including diametrically oppositely arranged foot pedals carried by the intermediate sleeve portion.

THOMAS E. CROCKETT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS 

